The present invention relates to integrated circuits. In particular, the invention relates to cooling of integrated circuits.
There is increasing demand within the electronics industry for improved thermal management of electronic components. Higher performance integrated circuits expend greater energy to achieve desired levels of performance, and generate substantially greater heat as a byproduct. Such integrated circuits also have higher circuit density and a correspondingly smaller surface area available for removal of generated heat.
The problem of heat removal is even greater for 3-D integrated circuits. 3-D integrated circuits are three dimensional in that they include layers of two-dimensional integrated circuits stacked vertically. Often, this is done by stacking two-dimensional integrated circuits face-to-face for two-layer stacks, or face-to-back for stacks of more than two layers. Typically, this requires that power and signal lines pass through a substrate upon which the two-dimensional circuit is integrated.
Some 3-D integrated circuits have been proposed that include channels in integrated circuit substrates through which a fluid flows to carry away heat. Such cooling channels, also called micro-fluidic channels, can be very effective at carrying away heat. However, as 3-D circuit integration of higher performance integrated circuits continues to develop, improvements in heat removal will be required.